I am restoring a spring wound 'vienna regulator'. The backboard is veneered in mahogany that has raised in a section to form a blister or bubble that is about 5 inches long and 2.3 inches wide. In addition, there are quite a few parallel splits in the raised area. By pressing very lightly on the 'bubble' I can tell that it's extremely fragile and very dry and brittle.
What would be the best way to soften and make this area more pliable so that I can reglue it. I plan on using hide glue to reattach it if everyone thinks that would be best. I've also thought about steaming the area with an iron and then pressing down so that the old glue will be reactivated. Any suggestions will be greatly appreciated.

Thanks, Jim

Scottie-TX

04-19-2007, 01:49 AM

EVERY case is different (pun in ten did). I have NEVER seen original veneer bubble. EVERY instance I've seen has been of someone reveneering the case and not properly glueing. Do you believe - are you certain this veneer is original ?
Can you use hide gloo? Depends. If it IS original, probably yes. If someone reveneered it, then it depends. It depends on what type adhesive was used. For example, if a contact cement was used to attach the veneer, then you'll need to use contact cement. Hide gloo won't bond in the presence of contact cement.
Yeah. I know. How in 'ell can you see under the bubble.
Possibility: Contact cement never dries - literally. If you can push down on the bubble and you can feel or hear it "tack" - try to stick? It's probly contact cement. If the test is negative, in all probability you can use hide or other gloos.

itspcb

04-19-2007, 09:12 AM

Tickntock,

You can get results by using an iron on a bubble, as you say the objective is to soften the glue and get it to go down again. Would not use steam which will expand the veneer.It worked on a case done by my 80 year old friend and true expert recently! This was a case of a circular supporting structure moving and separating from the veneer, I doubted it would go back , but it did.
Carefull not to burn the wood!

Let us know how you get on,

Peter
uk

tickntock1

04-19-2007, 10:02 AM

Scottie, I am sure that this is the original veneer. Apparently years ago, there was some kind of a water leak in the wall where the clock was hung and a considerable amount of moisture invaded the clock.
My concern is that since the veneer is so dry and brittle that attempting to press down on it so that it returns to a flat plane against the backboard will cause it to shatter into a million little pieces. This is why I'm wondering if steaming it to soften the veneer will allow it to become pliable enough so that it can be flattened. Is there some other method that will allow the veneer to become flexible enough so that it can be reattached?

Thanks, Jim

Thyme

04-19-2007, 12:15 PM

Scottie, I am sure that this is the original veneer. Apparently years ago, there was some kind of a water leak in the wall where the clock was hung and a considerable amount of moisture invaded the clock.
My concern is that since the veneer is so dry and brittle that attempting to press down on it so that it returns to a flat plane against the backboard will cause it to shatter into a million little pieces. This is why I'm wondering if steaming it to soften the veneer will allow it to become pliable enough so that it can be flattened. Is there some other method that will allow the veneer to become flexible enough so that it can be reattached?

Thanks, Jim

I'll preface this by saying I'm no veneer expert. (In fact of all clock repairs I hate doing veneer repair the most.)

I recently had an ogee that needed a sectional repair of missing veneer. I got some replacement veneer samples, but the piece I chose was on the thick side. There was no way I could flex the veneer enough to take the contour, without it splitting. So - I carefully bound it to a cylindrical container with rubber bands, using it as a form, and immersed it in water for several hours. It worked, in that I was able to glue the veneer to the case once it was pliable enough. (Clamping and banding it while gluing with hyde glue was a real headache, though.)

Anyway, if the steaming doesn't do the trick, you might try soaking it. Try a wet sponge applied as a poultice on it for several hours. That might work.

Scottie-TX

04-19-2007, 09:22 PM

Well; If it is original - and probably it is - it's sometimes a tuff call and at times I do take risks. Sometimes there's little choice. The good news is that very probably the adhesive used is also original and POSSIBLY it's bond can be broken because it may already be weak (I hope). As you opine - I do not favor wetting or steaming. I only see the wood expanding thereby and the bubble getting larger. As you, again; I'd be VERY concerned about shattering the bubble with pressure without treatment. Worst case scenario, I've slit bubbles. That provides a place to introduce glue and only the gap left by the incision suffices clearance to close the bubble. I hope that's not necessary. I'd hafta know more about the location of the bubble but I'd shoot for this: I'd try to break the bond of the veneer in a path closest to the bubble and as large an area as you dare (risk) . That would again have two benefits. 1. A place to introduce glue and 2. relief to compress the bubble - it now has a place to go.
There is one HUGE advantage of this method over the slit. If for example the wood rips in the process, it will be an irregular rip along the lines of grain. This kind of seam can be invisibly closed unlike a straight knife slice.

Joseph Bautsch

04-20-2007, 07:49 AM

Jim - Another method, and I have to give Richard Baker credit, is to drill a small hole in the center of the bubble and use a syringe and inject hot hide glue. Then clamp using a piece of wax paper over the veneer, and a piece of Styrofoam glued to a piece of wood. The Styrofoam will take the shape of the wood under the veneer with out causing damage to the veneer. Use white glue to glue the Styrofoam to the piece of wood. The wax paper wax paper will keep the Styrofoam from being glued to the veneer.